1. Field of the Invention
Apparatuses and methods consistent with the present invention relate to adjusting disparity in a three-dimensional image and a three-dimensional imaging device, and more particularly, to adjusting disparity in a three-dimensional image and a three-dimensional imaging device in which disparity in a three-dimensional image is adjusted in order to reduce visual fatigue occurring when viewing the three-dimensional image.
2. Description of the Related Art
Three-dimensional (3D) cameras, such as stereo cameras or multi-view cameras, generally capture left and right images using two or more cameras functioning similarly to human eyes, and cause a viewer to feel a stereoscopic effect due to disparities between the two images. Specifically, a user observes parallax due to the disparity between the two images captured by a 3D camera, and this binocular parallax causes the user to experience a stereoscopic effect.
FIG. 1 is a view illustrating various types of binocular parallax. In FIG. 1, when a user views a 3D image, the binocular parallax which the user sees can be divided into (a) negative parallax, (b) positive parallax, and (c) zero parallax. (a) Negative parallax means objects appear to project from a screen, and (b) positive parallax means objects appear to be behind the screen. (c) Zero parallax refers to the situation where objects appear to be on the same horizontal plane as the screen.
In 3D images, negative parallax generally has a greater stereoscopic effect than positive parallax, but has a greater convergence angle than positive parallax, so viewing positive parallax is more comforting to the human eyes. However, if objects in 3D images have only positive parallax, eyes feel fatigue even though eyes feel comfortable in the positive parallax. In the same manner, if objects in 3D images have only negative parallax, both eyes feel fatigue.
FIG. 2 is a view illustrating various types of 3D cameras in the related art. In FIG. 2, the 3D camera comprises (a) parallel 3D camera 210, (b) toe-in 3D camera 220, and (c) hybrid 3D camera 230.
The parallel 3D camera 210 having both lenses placed in parallel has an advantage in image compression/transmission and image processing, but is unable to converge on a single point like the eyes of the human. The toe-in 3D camera 220 has a convergence functionality, but vertical parallax is generated at the left and right edges of the 3D image. The distortion of the 3D image due to the vertical parallax causes visual fatigue. In the hybrid 3D camera 230, lenses and charge coupled devices (CCDs) move separately, and the convergence functionality is controlled without the vertical parallax, and thus it is possible to embody a 3D image with less visual fatigue.
However, it is difficult for the multi-view camera and other 3D cameras to be implemented in the same manner as the hybrid 3D camera 230.
Therefore, there is a need for methods to display 3D images captured by a multi-view camera and other 3D cameras, such as 3D images captured by the hybrid 3D camera 230.